Corkscrew



FIG. 1 is a top, side and front perspective view of a corkscrew showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a right side elevation view thereof, the left side elevation being a mirror image thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines depict environmental subject matter only and form no part of the claimed design. 

The ornamental design for a corkscrew, as shown and described. 